This invention relates to a method and apparatus for shooting simulation of ballistic ammunition where the targets are movable. More particularly, the invention relates to a shooting simulator where laser pulses are transmitted from a weapon within a solid angle relative to a reference line aligned with the sighting axis of the weapon. The laser pulses are reflected by the target. The target distance and its angle deviation from the reference line at the time of the shot are determined from the travel time of the reflected laser pulses and their position in the solid angle. The change in the position of the target during the projectile flight time, which corresponds to the target distance, is measured and compared with the measured angle deviation, and a score is registered depending on the results of this comparison. This invention also relates to an apparatus for carrying out this process.
In shooting with ballistic ammunition (in contrast with remote controlled ammunition), it is not only necessary to sight the target properly, but it is also important to set the angle of elevation between the axis of the weapon and the sighting line. The angle of elevation takes into account the curved projectile flight path on the basis of measured and estimated data regarding the target distance, type of ammunition, etc. When firing at moving targets, it is also necessary to take into account the projected change in position of the target during the projectile flight time. This change is in the form of the lead angle. The shot misses the target if the target is not sighted properly at the moment of firing, or if the angle of elevation or the lead angle is incorrect.
When shooting is simulated by means of laser beams which propagate linearly, then in the simplest form, control of the proper sighting of the target with laser beams transmitted along the sighting line is all that is necessary. However, for a correct ballistic evaluation of the simulated shot, the angle of elevation and lead angle relative to the sighting line must also be taken into account. In accordance with U.S. Pat. No. 3,257,741, a comparator device may be provided for this purpose to compare the actual target distance measured by the laser pulse time with the target distance estimated and set by the weapon operator.
With another system that is known from French Pat. No. 1,580,909, the laser beam is deflected with respect to the axis of the weapon by an angle which corresponds to the theoretical angle of elevation, so that the laser beam can hit the sighted target only if the actual angle of elevation corresponds to the theoretical angle of elevation. It is also known from the same publication that the laser beam can pass through a scanning pattern with respect to the sighting line so that the angle deviation of the target with respect to the sighting line can be quantified on the basis of the location in the scanning pattern of that portion of the laser radiation which is received at the target. Thus, the angle deviation can also be related to the angle of elevation and the lead angle.
All these known systems utilize additional data regarding weapon settings which must be input into the shooting simulation equipment by means of input and interface stations by the weapon system in analyzing a simulated shot. The shooting simulation and evaluation equipment must therefore be adapted to a given weapon system with regard to the data to be transferred and the interfaces required for this purpose. Thus, it cannot be used universally for any other weapon systems. With the known equipments, it is impossible to accurately take into account the lead with movable targets or to take into account a tilted weapon position relative to the vertical.
This invention is therefore based on the above-mentioned process which is known from German patent application No. 2,262,605, (corresponding to U.S. Pat. No. 3,927,480) which has the advantage that all data which reproduce the alignment of the weapon at the time when the shot is fired, relative to the position assumed by the target at the end of the projectile flight time, are measured and determined autonomously by the shooting simulation equipment so that no data transfer from the weapon system is necessary and no interfaces are required. Equipment operated according to this principle can therefore be designed for universal use with weapons systems of any type.
With this known process, the change in position executed by the target during the projectile flight time is measured by the fact that another laser beam is transmitted into the solid angle at the end of the projectile flight time, and the distance and deviation of the target are determined again. However, this is possible only when the transmission equipment and the solid angle reference line for the first and second laser pulses are exactly the same. Therefore, it is either necessary for the weapon to be kept motionless during the simulated projectile flight time or else the laser transmitter must be disconnected from the weapon after firing the shot and kept directionally constant, for example, by a gyroscope-stabilized platform. This, of course, is more expensive and leads to an unrealistic shooting operation, because under practical conditions, a weapon is moved immediately after firing a shot in order to change locations or to aim at another target. This method cannot be used at all in cases when the weapon must be moved under cover during the projectile flight time, for example, or when it must be shifted by a large amount.
Another disadvantage of the known process is that each laser pulse must cover a large solid angle simultaneously, so it must have a high intensity and therefore entails the danger of eye damage at a short distance from the weapon. Furthermore, the target deviation is determined by means of a direction-sensitive receiver which responds to the reflection pulses, so the accuracy of the measurement is limited.